M&S says

Perfect for achieving a flattering figure, our knickers feature a high leg cut to help give the impression of longer looking legs. Made with added stretch and designed to sit just under the waist, our pull-on knickers provide excellent cover and support for everyday comfort. Ornate lace detailing finishes off the look for truly elegant and feminine knickers.

* Buy 3 for the price of 2: Get 3 for 2 on selected women’s Knickers & Vests when purchased in one transaction at marksandspencer.com/en and in selected stores. Discount will be shown at checkout. Please check relevant delivery terms & conditions online. Eligible products must have the same delivery date and address for promotion to apply across all items. Offer does not apply to delivery charges. Subject to availability. Any refunds will take into account the discount.